<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        img{
            position: absolute;
            top: 2px;
        }
    </style>
</head>
<body>
    <img src="images/angel.gif" alt="">
    <script>
        var pic = document.querySelector('img');
        document.addEventListener('mousemove',function(e){
            //1.mousemove只要我们鼠标移动1px 就会触发这个事件
            //console.log(1);
            //2.核心原理：每次鼠标移动，都会获得最新的鼠标坐标，把这个x和y坐标做为
            // 图片的top和left 值就可以移动图片
            var x = e.pageX;
            var y = e.pageY;
            console.log('X坐标是'+x,'y坐标是'+y);
            //3.千万不要给left和top添加px 单位
            pic.style.left = x -50 +'px';
            pic.style.top = y -40 +'px';
        })
    </script>
</body>
</html>